Implant and delivery tool therefor

ABSTRACT

An implant comprises: (a) an implant body that comprises: (i) at least a first longitudinal portion of the implant body that defines a given outer diameter; and (ii) a recessed longitudinal portion of the implant body that is radially recessed with respect to the first longitudinal portion of the implant body, such that an outer diameter of the recessed longitudinal portion is less than the outer diameter of the first longitudinal portion; and (b) a cuff coupled to the implant body around the recessed longitudinal portion of the implant body such that an outer diameter of the cuff does not exceed the outer diameter of the first longitudinal portion. The cuff defines a plurality of holes that are configured to facilitate anchoring of the implant body with respect to the subject&#39;s tissue, by facilitating tissue growth into the holes. Other embodiments are also described.

FIELD OF THE INVENTION

The present invention relates generally to medical devices, andspecifically to apparatus and methods for use with percutaneousimplants.

BACKGROUND

Neurological disorders affect the nerves, muscles or the brain. Manyneurological disorders reduce or eliminate voluntary recruitment ofmuscles, which may result in loss of ability to perform motor tasks orto maintain systems that depend on muscle activity for their function.Other disorders may cause pain to adjacent tissues.

Neurostimulation is a clinical tool used to treat various neurologicaldisorders, and involves modulation of the nervous system by electricallyactivating fibers in the body.

SUMMARY OF THE INVENTION

For some applications of the invention, a system is provided comprisingan implant, and a delivery tool therefor. The implant has an antenna andat least one electrode. The delivery tool comprises a hollow needle thattypically has lateral openings. The delivery tool has discrete states.Typically, in a first state, the implant is entirely housed by theneedle, and/or the antenna is disposed proximally from the lateralopenings in the needle. Typically, in a second state, a distal portionof the implant is exposed out of the distal end of the needle, and/orthe antenna is aligned with the lateral openings. In a third state, theimplant is entirely disposed outside of the distal end of the needle.The system (i) facilitates testing of potential implantation sites forthe implant, and (ii) increases the safety of advancing implants closeto nerve tissue.

For some applications of the invention, the needle defines, at itsdistal end, a triple-grind bevel that defines (i) a primary grind, and(ii) two side-grinds that do not extend to meet each other to define apoint at a distal-most part of the needle. This triple-grind bevel maybe used for needles other than that of the delivery tool describedherein.

For some applications, the implant defines a recessed portion aroundwhich a cuff is disposed, the cuff facilitating anchoring of theimplant.

There is further provided, in accordance with an application of thepresent invention, apparatus for facilitating percutaneous delivery ofan implant to a target site of a body of a subject, the implantincluding an antenna, and the apparatus including:

a delivery tool including a hollow needle that defines lateral openingsin a wall of the needle, the hollow needle being configured to house theimplant,

the delivery tool being configured to define:

-   -   a first state, in which the implant is housed by the needle such        that the antenna is disposed proximally from the lateral        openings,    -   a second state, in which a distal portion of the implant is        exposed from a distal end of the needle, and the antenna is        aligned with the lateral openings, and    -   a third state, in which the implant is entirely disposed outside        of the distal end of the needle.

In an application, in the first state, the entire implant is disposedwithin the needle.

In an application, in the first state, the entire implant is disposedproximally from the lateral openings.

In an application, in the first state, the distal portion of the implantis aligned with the lateral openings.

In an application, the hollow needle is a hollow metal needle.

In an application, the hollow needle defines a triple-grind bevel at thedistal end of the needle, the triple-grind bevel defining:

a primary grind, and

two side-grinds that do not extend to meet each other to define a pointat a distal-most part of the needle.

In an application, the apparatus further includes the implant.

In an application:

the implant is an electrostimulator implant, and includes:

-   -   an implant body, the implant being injectable into tissue of a        subject along a longitudinal axis of the implant body;    -   a proximal electrode, and a distal electrode disposed on the        implant body distally from the proximal electrode, and

in the second state of the delivery tool, the distal electrode isexposed from the distal end of the needle.

In an application, in the first state of the delivery tool, the proximalelectrode and the distal electrode are disposed within the needle.

In an application, the antenna is configured to receive energywirelessly.

There is further provided, in accordance with an application of thepresent invention, a method for percutaneously delivering an implant toa target site of a body of a subject, the method including:

inserting into tissue of the subject a hollow needle of a delivery tool,while the delivery tool is in a first state, in which the implant isentirely housed within the needle and no portion of the implant isexposed through the lateral openings in the needle wall;

subsequently, switching the delivery tool to a second state, in which adistal portion of the implant is exposed from a distal end of theneedle, and a proximal portion of the implant is at least partiallyexposed through lateral openings defined by the needle wall; and

subsequently, switching the delivery tool to a third state, in which theimplant is entirely disposed outside of the distal end of the needle.

In an application, the method further includes, while the delivery toolis in the second state, advancing the delivery tool and the implantdistally within the body of the subject.

There is further provided, in accordance with an application of thepresent invention, a method for percutaneously delivering an implantthrough a region of a body of the subject to a target site of the body,the region including a fascia and non-fascia tissue, the methodincluding:

advancing, distally through the fascia, a hollow needle of a deliverytool, while the delivery tool is in a first state in which the implantis entirely housed within the needle;

switching the delivery tool to a second state in which a proximalportion of the implant is housed within the needle, and a distal portionof the implant is exposed from a distal end of the needle; and

while the delivery tool is in the second state, advancing the hollowneedle distally through non-fascia tissue.

In an application, the method further includes, prior to advancing thehollow needle distally through the fascia, switching the delivery toolinto the first state.

In an application, the method further includes, prior to switching thetool into the first state, advancing the hollow needle distally throughnon-fascia tissue toward the fascia while the tool is in the secondstate.

In an application, the method further includes, subsequently to the stepof advancing the hollow needle distally through the non-fascia tissuewhile the delivery tool is in the second state, switching the deliverytool to a third state, in which the implant is entirely disposed outsideof the distal end of the needle.

In an application, the method further includes, while the delivery toolis in the third state, releasing the implant from the delivery tool.

There is further provided, in accordance with an application of thepresent invention, apparatus for facilitating percutaneous delivery ofan implant to a target site of a body of a subject, the apparatusincluding:

a needle including:

-   -   a distal end; and    -   a proximal end,    -   the needle defining:        -   a lumen configured to facilitate passage of the implant            therethrough, and        -   a triple-grind bevel at the distal end of the needle, the            triple-grind bevel defining:            -   a primary grind, and            -   two side-grinds that do not extend to meet each other to                define a point at a distal-most part of the needle.

In an application, the needle defines lateral openings in a wall of theneedle, the openings being proximal from the distal end of the needle.

In an application, the needle is a metal needle.

In an application, the two side-grinds converge distally at an angle of65-85 degrees to each other.

In an application, the primary grind defines an angle of 15-25 degreeswith respect to a central longitudinal axis of the needle.

In an application, the side-grinds converge distally, but at thedistal-most part of the needle, the side-grinds are spaced apart by0.1-0.4 mm.

There is further provided, in accordance with an application of thepresent invention, a method for percutaneously delivering an implant toa target site of a body of a subject, the method including:

inserting the implant into the subject's tissue;

activating the implant to apply a current to the subject's tissue at afirst site within the tissue at a first power level;

measuring a response of the subject to the application of the current tothe first site at the first power level;

in response to detecting that the subject responded in a given manner tothe application of the current to the first site at the first powerlevel, iteratively applying current to the first site at iterativelylower power levels until detecting that, at a second power level, thesubject no longer responds, in the given manner, to the application ofcurrent to the first site; and

subsequently:

-   -   moving the implant to one or more further sites within the        subject's tissue and applying current to the tissue, at the one        or more further sites, at the second power level;    -   measuring a response of the subject to the application of        current to the subject's tissue at the one or more further        sites; and    -   in response to detecting that the subject responds, in the given        manner, to application of the current at the second power level        at a given one of the one or more further sites, implanting the        implant closer to the given site than to the first site.

In an application:

inserting the implant includes inserting the implant while the implantis at least partly disposed within a hollow needle of a delivery tool,

moving the implant includes moving the implant while the implant is atleast partly disposed within the hollow needle, and

activating the implant includes activating the implant while (i) theimplant is at least partly disposed within the hollow needle, and (ii)an electrode of the implant is exposed from a distal end of the hollowneedle.

In an application, activating the implant includes wirelessly activatingthe implant while an antenna of the implant is aligned with a lateralopening in a wall of the hollow needle.

In an application, moving the implant includes moving the implant whilethe electrode of the implant remains exposed from the distal end of thehollow needle.

There is further provided, in accordance with an application of thepresent invention, apparatus including:

an implant configured to be implanted in tissue of a subject, theimplant including:

-   -   an implant body that includes:        -   at least a first longitudinal portion of the implant body            that defines a given outer diameter; and        -   a recessed longitudinal portion of the implant body that is            radially recessed with respect to the first longitudinal            portion of the implant body, such that an outer diameter of            the recessed longitudinal portion is less than the outer            diameter of the first longitudinal portion; and    -   a cuff coupled to the implant body around the recessed        longitudinal portion of the implant body such that an outer        diameter of the cuff does not exceed the outer diameter of the        first longitudinal portion,    -   the cuff defining a plurality of holes that are configured to        facilitate anchoring of the implant body with respect to the        subject's tissue, by facilitating tissue growth into the holes.

In an application, the cuff extends less than 360 degrees around therecessed longitudinal portion.

In an application, each hole of the plurality of holes has a diameter of200-550 microns.

In an application, the cuff has a thickness of 200-550 microns.

In an application, the implant further includes an antenna, disposedwithin the recessed longitudinal portion.

In an application, the recessed longitudinal portion does not include adistal end or a proximal end of the implant.

In an application, the cuff includes a resilient material.

In an application, the apparatus further includes a delivery tool thatincludes a hollow needle through which the implant is slidable, and theouter diameter of the cuff is such that the cuff does not grip theinside of the hollow needle.

In an application, the hollow needle defines a triple-grind bevel at adistal end of the needle, the triple-grind bevel defining:

a primary grind, and

two side-grinds that do not extend to meet each other to define a pointat a distal-most part of the needle.

The present invention will be more fully understood from the followingdetailed description of applications thereof, taken together with thedrawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-C are schematic illustrations of a system comprising an implantand a delivery tool therefor, in accordance with some applications ofthe invention;

FIGS. 2A-H are schematic illustrations of a technique for using thedelivery tool to implant the implant, in accordance with someapplications of the invention;

FIGS. 3A-D are schematic illustrations of a tip of a needle of thedelivery tool, in accordance with some applications of the invention;and

FIGS. 4A-C are schematic illustrations of the implant, in accordancewith some applications of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Reference is made to FIGS. 1A-C, 2A-H, 3, and 4A-C, which are schematicillustrations of a system 20 and techniques for using the system, inaccordance with some applications of the invention. System 20 comprisesan implant 40, and a delivery tool 100 for percutaneous implantation ofthe implant.

Implant 40 comprises an implant body 42, circuitry 44 and an antenna 46disposed within the implant body, and at least one electrode 48 (e.g., aproximal electrode 48 p and a distal electrode 48 d) disposed on theoutside of the implant body. Implant 40 has a proximal portion 50 p(e.g., a proximal half) that includes a proximal end of the implant, anda distal portion 50 d (e.g., a distal half) that includes a distal endof the implant. Typically, at least one of electrodes 48 (e.g., a distalelectrode 48 d) is disposed at distal portion 50 d. Typically, antenna46 is disposed proximally from that at least one electrode 48. Forexample, antenna 46 may be disposed proximally from distal portion 50 d,such as within proximal portion 50 p.

At proximal portion 50 p (e.g., at the proximal end) of implant 40, theimplant (e.g., implant body 42) defines an implant-coupling 52 that isreversibly couplable to a complementary tool-coupling of tool 100.

Tool 100 comprises a hollow needle 102 at a distal part of the tool, anda control portion 104 at a proximal part of the tool, the controlportion typically comprising a handle 106. Needle 102 has a lateral wallthat circumscribes a longitudinal axis ax1 of the needle to define alumen along the longitudinal axis. Needle 102 defines lateral openings108 (e.g., longitudinal slits) in the lateral wall. Tool 100 isconfigured to define at least three states, which are shown in FIGS.1-C, respectively.

FIGS. 1A-C show implant 40 loaded in tool 100. In the first state (FIG.1A), implant 40 is housed by needle 102 such that antenna 46 is disposedproximally from openings 108. For some applications, in the first statethe entire of implant 40 is disposed proximally from openings 108 (i.e.,proximally along longitudinal axis ax1 of needle 102). Alternatively,and as shown, some of the implant (e.g., distal portion 50 d) is alignedwith openings 108 (i.e., disposed at the same part of longitudinal axisax1 of needle 102), and/or distally from the openings (i.e., distallyalong the longitudinal axis of needle 102). Typically, and as shown, inthe first state, all of electrodes 48 are disposed within needle 102(i.e., the lumen thereof). For example, and as shown, in the firststate, implant 40 may be disposed entirely within needle 102.

In the second state (FIG. 1B), distal portion 50 d of implant 40 isexposed from the distal end of needle 102, and antenna 46 is alignedwith openings 108 (i.e., disposed at the same part of longitudinal axisax1 of the needle). Typically, in the second state, electrode 48 d isexposed from the distal end of needle 102.

In the third state (FIG. 1C), implant 40 is entirely disposed outside ofthe distal end of needle 102.

Implant 40 is an electrostimulator implant, and drives electrodes 48 toapply current to tissue of the subject in which the implant isimplanted. Implant 40 is controlled and/or powered wirelessly, e.g., bytransmitting wireless signals from an extracorporeal controller (notshown). Such signals are received by antenna 46. Needle 102 is typicallymetallic. Openings 108 allow such wireless signals to pass into thelumen of needle 102. Other parts of needle 102 are relatively opaque tosuch signals. During implantation of implant 40, and before finaldeployment (i.e., release) of the implant, the implant is activated suchthat it drives electrodes 48 to apply current to the tissue, in order todetermine if its current location within the tissue is an effectivelocation for implanting the implant (e.g., by determining if its desiredeffect on the subject occurs). The inventors hypothesize that it isadvantageous to prevent the operator (e.g., the physician) frominappropriately and/or inadvertently activating implant 40 (e.g., at aninappropriate time). In the first state, the wireless signals cannotreach (or cannot sufficiently reach) antenna 46. Therefore, the testingof the position of implant 40 cannot be performed in the first state. Inthe second state, the wireless signals can reach antenna 46, andtherefore it is possible, in the second state, to test the position ofimplant 40. (Naturally, the wireless signals can reach antenna 46 alsowhen tool 100 is in the third state, because in the third state implant40 is entirely disposed outside of the distal end of needle 102.)

The use of openings 108 is particularly useful for applications in whichthe material from which needle 102 is formed is opaque to the wirelesssignals (e.g., a metal). For some applications, the material from whichneedle 102 is primarily formed may be transparent to the wirelesssignals (e.g., a polymer). For some such applications, needle 102 mayhave a metallic portion (e.g., a metallic shell radially inside,outside, or within the polymer, or as a distinct metallic longitudinalsection between more proximal and distal polymer longitudinal sections),at the part of the needle at which antenna 46 is disposed in the firststate of tool 100. The metallic portion inhibits the wireless signalfrom reaching (or sufficiently reaching) antenna 46, as describedhereinabove, mutatis mutandis. Therefore, in a similar way to thatdescribed hereinabove, such a needle would also preventinappropriate/inadvertent activation of implant 40 while tool 100 is inthe first state, but would allow activation of the implant while thetool is in the second state. In a similar way, for some applicationsneedle 102 may be primarily formed from a metal, but openings 108 arereplaced by a polymer portion of the needle.

The embodiments described above have the following in common:

-   -   The hollow needle has (i) a non-blocking longitudinal portion        that allows the wireless signal to reach the antenna while the        antenna is disposed in the non-blocking portion, and (ii) a        blocking longitudinal portion that is significantly more opaque        to the wireless signal than is the non-blocking portion, such        that it blocks the wireless signal from activating the implant        while the antenna is disposed in the blocking portion.    -   In the first state of the tool, the antenna is disposed in the        blocking portion of the needle.    -   In the second state of the tool, the antenna is disposed in the        non-blocking portion of the needle.    -   In the third state of the tool, the implant is entirely disposed        outside of the distal end of the needle.    -   Typically, the non-blocking portion is closer than the blocking        portion to the distal end of the needle.

For applications in which (i) in the first state all of electrodes 48are disposed within needle 102, and (ii) in the second state electrode48 d is exposed from the distal end of the needle, the differingposition of the electrodes between the first and second states mayfurther prevent inappropriate and/or inadvertent driving of the currentby implant 40. That is, in the first state, implant 40 cannot receivethe wireless signals, and electrodes 48 are not exposed for applicationof current, whereas in the second state, implant 40 can receive thewireless signals, and at least one of electrodes 48 is exposed forapplication of current.

It is to be noted that, in the context of the first, second and thirdstates of tool 100, the term “state” (including in the specification andthe claims) means a discrete pre-configured condition of the tool, suchas a condition in which the tool is configured to remain. Thus, tool 100being configured to define the states means that tool 100 has particularfeatures or elements that define the states and/or retain the tool inthe states. For example, tool 100 (e.g., control portion 104) maycomprise control elements 110 that enable switching between the states.

FIGS. 2A-H show steps in a technique for using tool 100 to implantimplant 40 in a subject, in accordance with some applications of theinvention. The example used is implantation of implant 40 close to atibial nerve 6 of the subject, and in a distal to proximal direction,but the technique may be used at other anatomical sites and/or in otheranatomical directions, mutatis mutandis. Each of FIGS. 2A-H shows alongitudinal cross-section and a transverse section of the lower leg 4of a subject. The longitudinal cross-section illustrates the advancementof needle 102 through the tissue, and the state of tool 100. Thetransverse cross-section provides more anatomical detail, andschematically shows the depth to which needle 102 has penetrated. In thetransverse cross-section, the element labeled 102 schematicallyrepresents needle 102. However, although in the transverse cross-sectionneedle 102 should extend into and/or out of the page, a more simplerepresentation is used for the sake of clarity.

Needle 102 (e.g., a tip 120 thereof) is percutaneously advanced into theleg (FIG. 2A). For some applications, and as shown, needle 102 isadvanced through the skin while tool 100 is in the first state, with tip120 thereby defining the leading edge of system 20, e.g., such thatneedle 102 penetrates the skin. (Alternatively, an incision is made inthe skin, and tool 100 is introduced via the incision, e.g., while inthe second state). Subsequently, tool 100 is switched to the secondstate (FIG. 2B). Subsequently, and while tool 100 is in the secondstate, it is advanced through non-fascia tissue (e.g., fat tissue,and/or connective tissue) 8 of the leg, typically until reaching afascia 10 (FIG. 2C). That is, system 20 is advanced through thenon-fascia tissue with implant 40 distal to needle 102, and defining theleading edge of system 20. Upon reaching a fascia 10, tool 100 isswitched to the first state (FIG. 2D), and advanced through the fasciawhile in the first state (FIG. 2E). Once through the fascia, the tool isswitched to the second state (FIG. 2F), and advanced through more tissue8 (FIG. 2G). As described hereinabove, in the second state it ispossible to determine if the current location of implant 40 within thetissue is an effective location for implanting the implant. Once asuitable location of implant 40 is achieved (FIG. 2G), tool 100 isswitched to the third state (FIG. 2H). Implant 40 is deployed (i.e.,released from tool 100) at the suitable location, e.g., automaticallyupon tool 100 being switched to the third state, or as a result of adistinct subsequent deployment step.

As described hereinabove, determining that implant 40 is in a suitablelocation for implantation is achieved by activating the implant and, forexample, detecting if the desired effect of the implant on the subjecthas occurred. It is hypothesized by the inventors that, for someapplications, such a technique may be limited when the implant isactivated to apply current at a single power level. For example, when asingle power level is used, if an effect on the subject is detected whenthe implant is at a first site, and an effect on the subject is alsodetected when the implant is at a second site, the technique will nothave provided information on which of the two sites is more suitable(e.g., closer to nerve 6). It is hypothesized by the inventors that sucha technique may be improved by varying the power level at which implant40 applies current to the tissue in which it is disposed. For example,if (1) after the effect is detected when the implant is at the firstsite, the implant is activated again, but using iteratively lower powerlevels until the effect is reduced (e.g., to below a threshold level,such as until the effect is not detected), and (2) when the lower powerlevel is used at the second site, the effect is detected (and/or isabove the threshold level), this indicates that the second site is moresuitable (e.g., closer to nerve 6) than is the first site.

There is therefore provided, a method for percutaneously delivering animplant to a target site of a body of a subject, the method comprising:

(1) inserting the implant into the subject's tissue;

(2) activating the implant to apply a current to the subject's tissue ata first site within the tissue at a first power level;

(3) measuring a response of the subject to the application of thecurrent to the first site at the first power level;

(4) in response to detecting that the subject responded in a givenmanner to the application of the current to the first site at the firstpower level, iteratively applying current to the first site at lowerpower levels, until detecting that, at a second power level, the subjectno longer responds, in the given manner, to the application of currentto the first site; and

(5) subsequently:

-   -   (a) moving the implant to one or more further sites within the        subject's tissue and applying current to the tissue, at the one        or more further sites, at the second power level;    -   (b) measuring a response of the subject to the application of        current to the subject's tissue at the one or more further        sites; and    -   (c) in response to detecting that the subject responds, in the        given manner, to application of the current at the second power        level at a given one of the one or more further sites,        implanting the implant closer to the given site than to the        first site.

For applications in which movement of the implant between the sitesbeing tested does not require further penetration of a fascia, thismovement of the implant between the sites is typically performed whilethe delivery tool remains in the second state.

Tip 120 is a beveled tip for penetrating tissue. It is hypothesized bythe inventors that beveled tips are important for penetrating fascia 10(and typically also skin 12), but that some other tissues (e.g., fattissue and/or connective tissue) can be penetrated by implant 40 itself.Thus, in the technique shown in FIGS. 2A-H, implant 40 is advancedthrough tissue 8 while tool 100 is in the second state, thereby (asdescribed hereinabove) facilitating identification of an effectivelocation for implanting implant 40. It is further hypothesized by theinventors that as implant 40 becomes close to a target nerve such astibial nerve 6, advancing the implant while tool 100 is in the secondstate reduces a likelihood of injuring the nerve or a nearby bloodvessel with tip 120.

It is to be noted that the transition of tool 100 between its states isperformed by retracting and advancing needle 102 with respect to controlportion 104 (e.g., changing the effective length of the needle), ratherthan by advancing and retracting implant 40. This allows implant 40,once a suitable location has been identified, to be deployed from tool100 without moving the implant with respect to the surrounding tissue(FIGS. 2G-H).

FIGS. 3A-D show detailed views of tip 120 of needle 102 of tool 100, inaccordance with some applications of the invention. Tip 120 has atriple-grind bevel that defines a primary grind 122 (alternativelytermed a primary bevel) and two side-grinds 124 (alternatively termedsecondary bevels, or lancets). Unlike other triple-grind needles,side-grinds 124 do not extend to meet each other to define a point(i.e., a distal point) at a distal-most part of needle 102 (i.e., at thevery tip of the needle). That is, primary grind 122 contributes to thepointedness of the distalmost part 126 of tip 120, but side-grinds 124do not. Thus, part 126 appears pointed when tip 120 is viewed from theside (e.g., when viewed such that primary grind 122 forms part of theoutline of the tip) (e.g., FIG. 3A view D), but appears blunt or roundedwhen the tip is viewed from above or below (e.g., when viewed such thatside-grinds 124 are both visible) (e.g., FIG. 3A views C and F, and FIG.3B). Therefore, side-grinds 124 converge toward distalmost part 126, buteven where they are closest to each other (i.e., at or near to part126), they are spaced apart by a distance d5.

For some applications, primary grind 122 defines an angle of 15-25(e.g., 18-22, such as 20) degrees with respect to the lateral walland/or central longitudinal axis ax1 of needle 102. For someapplications, side-grinds 124 converge distally at an angle alpha_1 of65-85 (e.g., 74-78, such as 76) degrees to each other (see FIG. 3B). Forsome applications, distance d5 is 0.1-0.4 mm (e.g., 0.16-0.28 mm, suchas 0.22 mm).

FIG. 3C shows a transverse cross-section of tip 120 at section III(shown in FIG. 3B), according to some applications of the invention. Forsuch applications, side-grinds 124 face away from primary grind 122.That is, side-grinds 124 are “underneath” the needle, and do noteliminate the sloped surface of primary grind 122. Hence the surface ofprimary grind 122 is visible in FIG. 3C. In transverse cross-section,the planes of side-grinds 124 are disposed at an angle alpha_2 that istypically 100-150 (e.g., 110-140, e.g., 120-140, such as 130) degreeswith respect to each other. For some applications, this is similar to a“back bevel point” needle tip, but without the side-grinds extending tomeet each other to define a point at the distal-most part of the needle.Therefore, angle alpha_2 may be described as a back bevel angle.

FIG. 3D shows a transverse cross-section of tip 120, according to somealternative applications of the invention. For such applications,side-grinds 124′ face toward primary grind 122. That is, side-grinds124′ are on the same side of the needle as primary grind 122, and at thelongitudinal portion of the needle at which they are disposed, theyeliminate the sloped surface of primary grind 122, leaving a ridge 125.In transverse cross-section, the planes of side-grinds 124′ are disposedat an angle alpha_3 with respect to each other. For some applications,this is similar to a “lancet point” needle tip, but without theside-grinds extending to meet each other to define a point at thedistal-most part of the needle. Therefore, angle alpha_3 may bedescribed as a lancet angle.

There is therefore provided, in accordance with some applications of theinvention, apparatus for facilitating percutaneous delivery of animplant to a target site of a body of a subject, the apparatuscomprising a needle that (1) comprises (a) a distal end; and (b) aproximal end, and (2) defines: (a) a lumen configured to facilitatepassage of the implant therethrough, and (b) a triple-grind bevel at thedistal end of the needle, the triple-grind bevel defining: (i) a primarygrind, and (ii) two side-grinds that do not extend to meet each other todefine a point at a distal-most part of the needle.

It is hypothesized by the inventors that tip 120 advantageously has both(i) the tissue-penetrating benefits of existing triple-grind needles,and (ii) a distalmost part that is relatively rounded and less likely toinjure a target nerve or an adjacent blood vessel, compared to suchexisting triple-grind needles.

FIGS. 4A-C show respective views of implant 40. FIG. 4A shows implant 40in its entirety. As described hereinabove, circuitry 44 and antenna 46are disposed within implant body 42, and the at least one electrode 48is disposed on the outside of the implant body. Also as describedhereinabove, at least one of electrodes 48 (e.g., distal electrode 48 d)is disposed at distal portion 50 d. Typically, another electrode (e.g.,proximal electrode 48 p) is disposed at proximal portion 50 p. Antenna46 is typically disposed proximally from electrode 48 d (e.g., withinproximal portion 50 p).

Implant 40 comprises a cuff 54, which circumscribes a recessedlongitudinal portion 56 of implant body 42. FIG. 4B illustrates implant40 with cuff 54 removed, thereby showing recessed longitudinal portion56. In the example shown, recessed longitudinal portion 56 is defined byat least part of proximal portion 50 p. However, recessed longitudinalportion 56 may alternatively or additionally be defined by at least partof distal portion 50 d.

Recessed longitudinal portion 56 is radially recessed with respect to atleast one other longitudinal portion of the implant body, such that anouter diameter of the recessed longitudinal portion is less than theouter diameter of the other longitudinal portion. In the example shown,the other longitudinal portion may be a longitudinal portion 58 proximalto portion 56 (e.g., another part of proximal portion 50 p), or alongitudinal portion 60 distal to portion 56 (e.g., part of distalportion 50 d). For example, an outer diameter d3 of recessedlongitudinal portion 56 is less than an outer diameter d4 of portion 58,and is also less than an outer diameter of portion 60 (which may be thesame as diameter d4), and therefore does not include the distal end orthe proximal end of the implant.

Cuff 54 is configured to be coupled to implant body 42 by being coupledto (e.g., wrapped around) recessed longitudinal portion 56 such that,when the cuff is coupled to portion 56, an outer diameter dl of the cuffdoes not exceed diameter d4. For some applications, cuff 54 extends lessthan 360 degrees (e.g., 340-355 degrees) around implant body 42.Typically, cuff 54 has a thickness of 100-500 (e.g., 200-250, such as225) microns.

Cuff 54 defines a plurality of holes 62. Each hole 62 may have adiameter of 200-550 (e.g., 280-340) microns. Cuff 54 typically comprisesa resilient material. For some applications, cuff 54 comprises polyetherether ketone, polyethylene terephthalate, fluorinated ethylenepropylene, polyimide, acrylic, nylon, polytetrafluoroethylene, orpolyetherimide (e.g., Ultem). This material and/or holes 62 increase theresistance of cuff 54, and therefore implant 40, to movement onceimplanted in tissue (e.g., the cuff grips the tissue). That is, cuff 54serves as an anchor. Because diameter dl does not exceed diameter d4,cuff 54 does not grip the inside of needle 102 (i.e., does not increasefriction of the implant against the inside of the needle), and therebydoes not interfere with movement of implant 40 within the needle duringdelivery and deployment of the implant. Holes 62 are further configuredto facilitate anchoring of implant 40 with respect to the tissue, byfacilitating tissue growth into the holes.

FIG. 4C shows implant 40 with electrodes 48 and most of implant body 42removed, thereby showing antenna 46 and circuitry 44. For someapplications, and as shown, antenna 46 is disposed in recessedlongitudinal portion 56.

It is to be noted that for some applications tool 100 may be used todeliver implants other than implant 40. For example, tool 100 may beused to deliver a different electrostimulator implant, or an implantthat is not an electrostimulator implant. It is to be further notedthat, for some applications, needle 102 (e.g., tip 120 thereof) may beused in delivery tools other than tool 100. It is to be further notedthat needle 102 may be useful for applications other than percutaneousimplantation of an implant.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather, the scope of the present inventionincludes both combinations and subcombinations of the various featuresdescribed hereinabove, as well as variations and modifications thereofthat are not in the prior art, which would occur to persons skilled inthe art upon reading the foregoing description.

1-27. (canceled)
 28. Apparatus comprising: an implant configured to beimplanted in tissue of a subject, the implant comprising: an implantbody that comprises: at least a first longitudinal portion of theimplant body that defines a given outer diameter; and a recessedlongitudinal portion of the implant body that is radially recessed withrespect to the first longitudinal portion of the implant body, such thatan outer diameter of the recessed longitudinal portion is less than theouter diameter of the first longitudinal portion; and a cuff coupled tothe implant body around the recessed longitudinal portion of the implantbody such that an outer diameter of the cuff does not exceed the outerdiameter of the first longitudinal portion, the cuff defining aplurality of holes that are configured to facilitate anchoring of theimplant body with respect to the subject's tissue, by facilitatingtissue growth into the holes.
 29. The apparatus according to claim 28,wherein the cuff extends less than 360 degrees around the recessedlongitudinal portion.
 30. The apparatus according to claim 28, whereineach hole of the plurality of holes has a diameter of 200-550 microns.31. The apparatus according to claim 28, wherein the cuff has athickness of 200-550 microns.
 32. The apparatus according to claim 28,wherein the implant further comprises an antenna, disposed within therecessed longitudinal portion.
 33. The apparatus according to claim 28,wherein the recessed longitudinal portion does not include a distal endor a proximal end of the implant.
 34. The apparatus according to claim28, wherein the cuff comprises a resilient material.
 35. The apparatusaccording to claim 28, further comprising a delivery tool that comprisesa hollow needle through which the implant is slidable, wherein the outerdiameter of the cuff is such that the cuff does not grip the inside ofthe hollow needle.
 36. The apparatus according to claim 35, wherein thehollow needle defines a triple-grind bevel at a distal end of theneedle, the triple-grind bevel defining: a primary grind, and twoside-grinds that do not extend to meet each other to define a point at adistal-most part of the needle.